The Bel-Art Scienceware F371900001 Spinfinity octagonal-shaped stir bar with built-in pivot ring has a purple hard-plastic casing and an internal magnet made from alnico V (an alloy of aluminum, nickel, iron, and cobalt) for a range of laboratory stirring applications. The octagonal shape creates more turbulence and a stronger vortex than a round, cylindrical shape or a polygonal shape. The magnet sits inside a hard plastic casing that provides more wear resistance than polytetrafluoroethylene (PTFE), for mixing abrasive solutions such as granular slurries. A built-in pivot ring minimizes contact between the bar and the container to help reduce vibration and wear during stirring. Its purple color provides quick identification. The bar measures 3" (76.2 mm) by 0.5" (12.7 mm) (L x OD, where L is the length, the horizontal distance from left to right, and OD is the outside diameter, or the circumference). The casing material is FDA approved for use in food, drug, and cosmetic applications.
Magnetic stir bars (sometimes called stirring bars, spin bars, or fleas) are used to stir a liquid or solution in biological, chemical, medical, and research laboratory applications. The stir bar is placed inside a container of liquid or solution that is seated on a magnetic stirrer (also called a magnetic mixer), which is a laboratory device that creates a rotating magnetic field using a rotating magnet or multiple stationary electromagnets. The rotating magnetic field causes the bar to spin, which stirs the liquid or solution. Stirring bars are offered in a variety of sizes and shapes, and they are encased in materials such as glass or plastic to help prevent contamination of the liquid or solution, to reduce friction, and to provide resistance to chemicals, abrasion, and heat. The bar may have a pivot ring or pivot point to minimize contact with the container, reduce friction, and improve its spinning. The size and shape of the container and the volume and viscosity of the liquid or solution to be stirred determine which stir bar shape, size, and casing will suit a particular application.
Bel-Art Products manufactures scientific products, including labware, testing equipment, and safety supplies, under the Bel-Art and Scienceware brands. The company, founded in 1946, is headquartered in Wayne, NJ.